A measuring tape represents a flexible form of linear rule, typically consisting of a ribbon or tape of cloth, plastic, fiberglass, or metallic strip of a uniform width containing measurement markings along its length. This style of measuring device provides advantages over a traditional fixed rule in that it is collapsible and easily stored in a coiled form. One common form of tape measure that is well known in the construction industry retains the measuring tape by coiling it around a spool contained within a protective housing. The measuring tape may be retracted into the housing by hand winding the tape or by releasing a spring lock so the winding action of the spring retracts the tape.
Measuring tapes are often used in locations where particulate matter, such as sawdust, dirt, and powders from metal or masonry products, and water are present. In typical applications, measuring tapes are placed onto a work surface and a measurement is read between two or more points. When used in this manner debris contained on the work surface may adhere to and accumulate on the tape. Subsequent retraction of the tape may transport the debris inside the protective housing where it becomes trapped, unable to exit through the housing's small passageway. Once debris is trapped inside the tape measure's protective housing, it continues to accumulate and eventually foul the tape measure's internal mechanisms, sometimes rendering the tape inoperable. Over time, in addition to lost time and aggravation to the user, the lifespan of the tape is greatly reduced.
U.S. Pat. No. 4,228,589 to Chemay discloses a tape measure for underwater use. This tape measure is described as reliable, durable and effective for underwater work. However, instead of preventing moisture from entering, it is described as easily disassembled for inspection and cleaning without tools.
U.S. Pat. No. 6,477,785 to Hsu discloses a measuring tape that is designed for fast and easy retraction of tape measures. The retracting mechanism is a hand crank that engages a reverse gear to retract the tape. No mechanism for cleaning the tape is disclosed.
U.S. Pat. No. 8,567,085 to Roeske discloses a retractable measuring tape containing an opening in the tape housing. The opening, when the tape is in use, is sealed with a plug. The plug can be detached from the housing by a user to access the interior of the housing to remove debris therein.
Therefore, there remains a need for a measuring tape that retracts quickly but does not transport particulate materials and water into its protective housing.